First time I've posted but I've managed to graduate from c25k now having had to start again after a knee injury kept me out for two months.
If I can offer any advice then it would be listen to your body, I had a niggle but ran anyway and ended up annoyed and disappointed with myself. Once my knee started to recover using the weight machines at the gym definitely helped and restored confidence in it.
Good luck to all those currently working through the plan and to those considering it then it is definitely worth it!